MCDB 1150 Class 9 - Enzymes

These flashcards cover important vocabulary and concepts related to enzymes, their functions, characteristics, and mechanisms of action.

Active site

The location on the enzyme where substrates bind and undergo a chemical reaction.

Activation energy (EA)

The energy barrier that must be overcome for a chemical reaction to occur.

Catalyst

A substance that speeds up a reaction by lowering the activation energy without being consumed in the process.

Free energy (ΔG)

The energy available to do work in a system, calculated as the difference between the free energy of products and reactants.

Exergonic reaction

A reaction that releases free energy (ΔG < 0), indicating that it occurs spontaneously.

Endergonic reaction

A reaction that requires an input of energy (ΔG > 0) to occur.

Substrate

The reactant that binds to an enzyme and is converted into products.

Enzyme specificity

The concept that each enzyme typically catalyzes one specific reaction or a specific type of reaction.

Ribozyme

A small RNA molecule that has catalytic properties and can alter chemical bonds.

Competitive inhibition

A type of enzyme regulation where a molecule similar in shape and size to the substrate competes for the active site.

Allosteric regulation

A form of enzyme regulation where a molecule binds to an enzyme at a site other than the active site, causing a change in enzyme shape.

Positive regulation

The activation of an enzyme or increase in its activity by effectors or substrate.

Negative regulation

The inhibition of an enzyme's activity by inhibitors.

Enzyme denaturation

A process where the three-dimensional structure of the enzyme is disrupted, leading to loss of function.

Coupling reactions

The process of linking energetically unfavorable reactions to favorable ones to drive the overall reaction.